Social media and other technologies continue to drive the recording and archiving of large amounts of data, including voice, video and other high data rate files. In spite of inroads made by solid-state drive (SSD) and other non-magnetic mass storage technologies, the computer industry continues to look to the evolution of magnetic recording (so-called “HDD”) technologies to satisfy the rapidly-increasing worldwide data storage demand.
One such technological evolution is a magnetic recording technique referred to as Heat Assisted Magnetic Recording (“HAMR”). Increasing storage densities require hard drive platter materials of increased magnetic coercivity. Such materials in turn require increasingly (and impractically) large magnetic fields to align the ferrous molecules below the write head and thus perform recording operations. However, it is known that the coercivity can be temporarily decreased for recording purposes by heating the recording position on the recording medium prior to applying the recording magnetic field. HAMR recorders pulse a laser beam from a laser diode focused on the recording position to heat the medium at the point of recording just prior to effecting the magnetic recording.
Thus, HAMR effectively requires two driver pulse streams, one to drive the pre-heat laser diode and one to drive the magnetic write head. Structures and techniques associated with signal drivers for current-technology HDD magnetic recording head technologies may not be suitable for HAMR and other advanced technologies. Likewise, structures and techniques associated with laser diode drivers used in current-technology optical recorders (e.g., CD, DVD, etc.) may not be suitable for HAMR and other ultra-density recording techniques. Tracking magnitude and timing parameters associated with the two pulse streams over temperature, process, and bias conditions may help to achieve planned HAMR write densities.